“Side effects” include but are not limited to: generating output, explicit use of require or include, connecting to external services, modifying ini settings, emitting errors or exceptions, modifying global or static variables,reading from or writing to a file, and so on.

다음은 부작용이 모두 포함된 코드의 예입니다. 즉, 피해야 할 예:

The following is an example of a file with both declarations and side effects;i.e, an example of what to avoid: